The disclosed embodiments relate to a medical device. Specifically, the disclosed embodiments relate to a guide wire to be inserted into a body cavity for treatment or examination.
Various conventional medical devices are available for treatment or examination by insertion into a tubular organ (such as a blood vessel, a gastrointestinal tract, and a urinary duct), or into a body tissue. For example, Japanese Unexamined Patent Application Publication No. 2007-501648 discloses a guide wire including a core wire and a coil body covering an outer surface of a distal portion of the core wire. The coil body includes a straight section that extends distally in a straight state from the proximal end of the coil body, and a bent section arranged distally of the straight section.
In a condition known as chronic total occlusion (CTO), a blood vessel exhibits a relatively serious degree of stenosis. To treat the stenosis, it is preferable to bend the guide wire close to its distal end in order to allow the guide wire to pass through a slight gap in the stenosis portion, as performed in the guide wire described in Japanese Unexamined Patent Application Publication No. 2007-501648.
However, when the guide wire is bent in such a manner, a gap forms between element wires in the bent section. As a result, a fragment of a calcified lesion in the stenosis portion may enter the gap between element wires and interfere with the progression of the guide wire into the blood vessel. The guide wire will become stuck in the stenosis, decreasing the maneuverability of the guide wire as it passes through the stenosis portion.
Thus, because of the gap formed between element wires in the bent portion of the guide wire, even the guide wire described in Japanese Unexamined Patent Application Publication No. 2007-501648 may not be able to pass through the stenosis portion due to the interference between the bent section and the lesion. There is room for improvement in this regard.